It is well known to encapsulate components within a plastic molding die cavity by rigidly affixing such components to or through the walls of the cavity. It is also known to avoid the appearance of holding devices at the surface of the molded product by providing retractable holding devices which retract out of the molding cavity while the molding material is "setting up." An example of the latter technique is shown in L. H. Morin U.S. Pat. No. 3,420,929, granted Jan. 7, 1969. It is also possible for the holding devices to retract into the center of the molded product, as shown in R. K. Piotrovosky U.S. Pat. No. 4,470,784, granted Sep. 11, 1984. Such prior art holding devices and techniques, however, do not hold the encapsulated component in a precisely defined position, and hence are of limited usefulness. In some applications, for example, the encapsulated components must maintain precise positions relative to other encapsulated components or with respect to the exterior contours of the molded product.
The problem of precisely positioning encapsulated components within an injection molding cavity can be further complicated by two additional factors. If the component to be encapsulated is not rigid, the problem of holding it in a precise position is far more difficult. Furthermore, the dimensions of the molded product may be such that very little leeway exists for positioning the encapsulated component away from the surfaces of the mold. If the component is not precisely and firmly positioned in the interior of a thin molding cavity, for example, a problem called "component breakout" occurs in which some or all of the encapsulated component is visible at the surface of the molded product. Such breakout is normally grounds for rejecting the product.